[Navy SEAL Marcus] Luttrell noted that, during hell week, if any candidate thought, "Oh my god I still have several days of this to go through," that candidate dropped out. The ones who survived were the ones who relentlessly focused on one thing and one thing only--taking the next step. 
“This then involved me working backward from the desired result (me being proficient in the movement) to where I currently was (being absolute shit in the movement). I set myself a few micro goals in between the two, wrote them down, and started working toward them, one at a time. This allowed me to only look at the next small, seemingly achievable goal, instead of at one large, very down-the-road, daunting goal that didn’t seem obtainable.” 
“Finish the design.” “Ship the product.” “We’re behind.” “There are more bugs.”
You only have what’s in front of you. The actions you can take, however small. The smaller the better. Focus on the next small, seemingly achievable goal. Build a path, a trajectory. Trajectory is what matters. The trajectory is what takes you to a destination.